This year my SHB problem is vastly improved. Last year there were many many and hard to control. I took several of your suggestion which I attribute to this favorable improvement. Thought I would share my thoughts.
1. Only used small grease patties that could be consumed quickly. In fact I have stopped using them.
2. Use all screened bottom boards.
3. I installed SHB traps on frames and keep filled with vinegar.
4. I am not sure if the early treatment of Api Life Var affected the SHBs directly.
5. Make every attempt to keep hives relatively same strenght.
6. Requeened hives most succeptable to he SHB last season.
Hope youre all doing as well.